Field data
  • Janka hardness 540 lbfred oak ≈ 1,290 lbf
  • Density ≈ 31 lb/ft³specific gravity 0.45 at 12% MC
  • Shrinkage — tangential 7.8%flatsawn width, green → ovendry
  • Shrinkage — radial 4.2%quartersawn width
  • T/R ratio 1.9 : 1higher = more cupping in flatsawn stock

Shop notes The "Hem" in Hem-Fir — even-grained, machines better than eastern hemlock, common in doors and moldings.

Seasonal movement at a glance

Width change for western hemlock across a typical indoor year — 6% moisture content in the heated winter to 12% in a humid summer:

Board widthFlatsawnQuartersawn
6″ 3/32″ (0.100″) 1/16″ (0.054″)
12″ 3/16″ (0.201″) 3/32″ (0.108″)
24″ 13/32″ (0.401″) 7/32″ (0.216″)
36″ 19/32″ (0.602″) 5/16″ (0.324″)

Run your own numbers

Different width, different climate swing — the calculator below is preset to western hemlock:

Board & conditions
Grain
Conditions given as

Typical swings:

Western Hemlock questions

How much does western hemlock move with the seasons?

A 12″-wide flatsawn western hemlock board moves about 3/16″ across a typical indoor swing from 6% to 12% moisture content; quartersawn, about 3/32″. Its tangential shrinkage is 7.8% and radial 4.2% (green to ovendry) — a moderate-movement wood.

How hard is western hemlock?

Western Hemlock rates about 540 lbf on the Janka scale — soft enough to dent in daily use (red oak is roughly 1,290 lbf). Density runs about 31 lb/ft³ at indoor moisture levels.

Is western hemlock good for wide panels and tabletops?

Yes, with normal precautions: its 1.9:1 tangential-to-radial ratio is moderate. Still fasten solid tops so they can move across their width.

Similar species

Red Pine · Black Spruce · Baldcypress · Jack Pine · Sitka Spruce · Alaska Yellow-Cedar

Shrinkage, specific gravity, and hardness from the Wood Handbook, FPL-GTR-282 (2021 edition), USDA Forest Products Laboratory (public domain). Values are species averages — individual boards vary with growth conditions and how they were dried.